AP_GPS: removed nav_setting default

not needed, and apparently caused issue with xcode 5.1

libraries/AP_GPS/AP_GPS_406.h

@@ -34,7 +34,7 @@ public:
     AP_GPS_406() : AP_GPS_SIRF() {}
 
     // Methods
-    virtual void        init(AP_HAL::UARTDriver *s, enum GPS_Engine_Setting nav_setting = GPS_ENGINE_NONE);
+    virtual void        init(AP_HAL::UARTDriver *s, enum GPS_Engine_Setting nav_setting);
 
 private:
     void                _change_to_sirf_protocol(void);

libraries/AP_GPS/AP_GPS_Auto.h

@@ -24,7 +24,7 @@ public:
     AP_GPS_Auto(GPS **gps);
 
     /// Dummy init routine, does nothing
-    virtual void        init(AP_HAL::UARTDriver *s, enum GPS_Engine_Setting nav_setting = GPS_ENGINE_NONE);
+    virtual void        init(AP_HAL::UARTDriver *s, enum GPS_Engine_Setting nav_setting);
 
     /// Detect and initialise the attached GPS unit.  Updates the
     /// pointer passed into the constructor when a GPS is detected.

libraries/AP_GPS/AP_GPS_HIL.h

@@ -32,7 +32,7 @@ public:
 		_updated(false)
 		{}
 
-    virtual void        init(AP_HAL::UARTDriver *s, enum GPS_Engine_Setting nav_setting = GPS_ENGINE_NONE);
+    virtual void        init(AP_HAL::UARTDriver *s, enum GPS_Engine_Setting nav_setting);
     virtual bool        read(void);
 
     /**

libraries/AP_GPS/AP_GPS_MTK.h

@@ -37,7 +37,7 @@ public:
 		_payload_counter(0)
 		{}
 
-    virtual void        init(AP_HAL::UARTDriver *s, enum GPS_Engine_Setting nav_setting = GPS_ENGINE_NONE);
+    virtual void        init(AP_HAL::UARTDriver *s, enum GPS_Engine_Setting nav_setting);
     virtual bool        read(void);
     static bool _detect(uint8_t );
 

libraries/AP_GPS/AP_GPS_MTK19.h

@@ -41,7 +41,7 @@ public:
         _fix_counter(0)
 		{}
 
-    virtual void        init(AP_HAL::UARTDriver *s, enum GPS_Engine_Setting nav_setting = GPS_ENGINE_NONE);
+    virtual void        init(AP_HAL::UARTDriver *s, enum GPS_Engine_Setting nav_setting);
     virtual bool        read(void);
     static bool 		_detect(uint8_t );
 

libraries/AP_GPS/AP_GPS_NMEA.h

@@ -70,7 +70,7 @@ public:
     /// Perform a (re)initialisation of the GPS; sends the
     /// protocol configuration messages.
     ///
-    virtual void        init(AP_HAL::UARTDriver *s, enum GPS_Engine_Setting nav_setting = GPS_ENGINE_NONE);
+    virtual void        init(AP_HAL::UARTDriver *s, enum GPS_Engine_Setting nav_setting);
 
     /// Checks the serial receive buffer for characters,
     /// attempts to parse NMEA data and updates internal state

libraries/AP_GPS/AP_GPS_None.h

@@ -11,7 +11,7 @@ class AP_GPS_None : public GPS
 public:
 	AP_GPS_None() : GPS() {}
 
-    virtual void        init(AP_HAL::UARTDriver *s, enum GPS_Engine_Setting nav_setting = GPS_ENGINE_NONE) {
+    virtual void        init(AP_HAL::UARTDriver *s, enum GPS_Engine_Setting nav_setting) {
 		_port = s;
     };
     virtual bool        read(void) {

libraries/AP_GPS/AP_GPS_SIRF.h

@@ -38,7 +38,7 @@ public:
 		_msg_id(0)
 		{}
 
-    virtual void        init(AP_HAL::UARTDriver *s, enum GPS_Engine_Setting nav_setting = GPS_ENGINE_NONE);
+    virtual void        init(AP_HAL::UARTDriver *s, enum GPS_Engine_Setting nav_setting);
     virtual bool        read();
 	static bool         _detect(uint8_t data);
 

libraries/AP_GPS/AP_GPS_UBLOX.h

@@ -57,7 +57,7 @@ public:
 		{}
 
     // Methods
-    virtual void                    init(AP_HAL::UARTDriver *s, enum GPS_Engine_Setting nav_setting = GPS_ENGINE_NONE);
+    virtual void                    init(AP_HAL::UARTDriver *s, enum GPS_Engine_Setting nav_setting);
     virtual bool                    read();
     static bool _detect(uint8_t );